Best Bluetooth keyboard alternatives to Surface Pro Type Cover

Just can't bring yourself to like the Surface Pro Type Cover? That's okay, here are some other options for your typing pleasure!
Microsoft's Surface Pro 3 and Surface Pro 4 are versatile devices that you can use as tablets or laptops. While Microsoft's Type Cover remains the best fit for its Surface line because of the benefits it confers, it is expensive and might not be for everyone.
Here's our roundup of some awesome third-party Bluetooth alternatives that are compatible with the Surface Pro 3 and 4.